Balloon catheter having a retractable sheath

ABSTRACT

An intravascular balloon catheter device includes an outer member disposed about an inner member. A balloon has a proximal portion which is connected to the outer member and a distal portion which is connected to the inner member. A sheath is disposed about the outer member and adapted for movement relative to the balloon. A coating with a therapeutic agent is provided on at least the distal portion of the balloon. The distal portion fits snugly into the sheath so as to provide a substantially watertight engagement therebetween when inside the sheath. The sheath is configured to prevent the proximal portion of the balloon from inflating to a diameter larger than the sheath.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. application Ser. No.15/241,606 filed Aug. 19, 2016, which is a continuation-in-part of U.S.application Ser. No. 14/990,477 filed Jan. 7, 2016, which claims thebenefit of U.S. Application No. 62/102,770, filed Jan. 13, 2015, andInternational Application No. PCT/US2014/046616, filed Jul. 15, 2014,which claims the benefit of U.S. Provisional Application No. 62/012,382,filed Jun. 15, 2014 and U.S. Provisional Application 61/846,095, filedJul. 15, 2013. The disclosures of all of which are incorporated hereinby reference as if restated in their entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention generally relate toballoon catheters used in surgical procedures.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates in general to balloon catheters that are used insurgical procedures. In particular, this invention relates to animproved structure for such a balloon catheter having a retractablesheath that can quickly and easily adjust the length of the inflatedportion of the balloon and a locking mechanism for selectively retainingthe sheath in the desired position for use.

In many surgical procedures, such as but not limited to percutaneoustransluminal angioplasty procedures, a catheter having a selectivelyinflatable portion provided thereon (commonly referred to as a ballooncatheter) is used to open a blockage and/or place a stent in a bloodvessel. To accomplish this, a user must select one of various sizedballoons to match the blood vessel structure and the length of thetreatment area. The balloon of the catheter is initially positioned at adesired zone of attention within the blood vessel. Then, the balloon ofthe catheter is inflated so as to expand into engagement With an innersurface of the blood vessel, thereby expanding the blockage. If desired,an expandable stent can be disposed about the balloon of the cathetersuch that when the balloon is inflated, the stent is expanded intoengagement with the inner surface of the blood vessel. The balloonand/or the stent is often treated with medication that is delivered bycontact with the surface of the blood vessel when the balloon and/orstent is deployed. In either event, the balloon is subsequently deflatedafter use.

It is important that the balloon be properly sized to the treatmentarea. If a balloon catheter is too long, the balloon may damage thesurrounding tissue. If a balloon is too short, the treatment may beineffective or require time-consuming repetition. Therefore, carefacilities are forced to stock many different size balloon catheters andmedical care providers must spend time carefully selecting the properlysized balloon catheter. What is needed is a variable length ballooncatheter. Therefore, it Would be desirable to provide an improvedstructure for such a balloon catheter having a retractable sheath thatcan quickly and easily adjust the length of the portion of the balloonto be inflated and a locking mechanism for selectively retaining saidsheath in the desired position for use.

Due to internal pressure, shape, and texture, a partially exposedballoon catheter would have a natural tendency to escape the retractablesheath when inflated. This is much like how a partially protrudingWatermelon seed has a natural tendency to entirely escape a person'slips, due to the watermelon seed's shape and texture. Here, the samephenomenon applies to a partially exposed balloon catheter from asheath, though the situation is further complicated by the internalpressure of the balloon. Therefore, it would be desirable toadditionally provide a mechanical stop in conjunction with the devicewhere said mechanical stop serves to prevent the balloon from entirelyescaping the retractable sheath when the balloon is inflated. Further,the mechanical stop can be used to adjust the effective area of theballoon catheter by controlling the length of the balloon permitted toextend from the sheath.

Recently, medical practitioners have realized that drug coatings may beapplied to the outer surface of the intravascular balloons to increasethe effectiveness of medical treatment. These so called “drug coatedballoons” are exposed to blood and other intravascular fluids upon beinginserted into a person's vascular system. This may result in thepremature activation, elution, dilution, and loss of the drug coating onthe way to the treatment zone. Therefore, it would be desirable toprovide a watertight seal between the balloon and the sheath such thatthe medicated balloon is not exposed to intravascular fluids until theballoon reaches the treatment zone.

The present invention is directed to an improved structure for a ballooncatheter having a retractable sheath that can quickly and easily adjustthe length of the inflated portion of the balloon and a lockingmechanism for selectively retaining the sheath in the desired positionfor use. The balloon catheter assembly includes an inner member and anouter member that is disposed about the inner member. The outer memberincludes an inflatable balloon. A sheath is disposed about the outermember for movement relative to the balloon so as to selectively exposesome or all of the balloon for inflation. The balloon catheter assemblyincludes a clamp for selectively securing the sheath at a desiredposition relative to the balloon. The inner member may comprise a seriesof indentations or protrusions that engage the clamp such that the usermay selectively control the location of the retractable sheath relativeto the balloon.

The assembly may further include a mechanical stop that is configured toselectively secure the balloon and prevents it from entirely escapingthe sheath when the balloon is inflated. The assembly may comprise aseries of graduated markers, such as radiopaque markers, that indicatethe position of the balloon relative to the retractable sheath. Theballoon may further comprise a strength collar, such as an annulus,located on the distal end of the retractable sheath.

Additionally, the balloon and the sheath may form a substantiallywatertight engagement with one another. This seal may prevent themedicated coating from being prematurely removed, eluted, or activatedprior to the assembly being properly located at the treatment site. Inexemplary embodiments of the present invention, the assembly may furthercomprise a cap that provides a substantially watertight engagementbetween said cap and the sheath when the balloon is in a retractedposition such that the cap abuts the sheath. The balloon may furthercomprise a lubricious coating between the outer surface of the balloonand the inner surface of the sheath which allows the balloon to moverelative to the sheath without disturbing the medicated coating.

It may be advantageous to facilitate incremental adjustments to theexposed portion of the balloon. Additionally, or in the alternative, itmay be advantageous to permit recapture and redeployment of the balloon.Balloons are often neatly folded and tightly packed into the smallestpossible size sheath because the devices are required to enter andnegotiate the patient's oftentimes narrow and winding vascular system.Once the balloon is deployed it is difficult to recover the balloonwithout wear or damage to the balloon. Regardless, it is also difficultto repackage the balloon in as neat and tidy a manner as it wasoriginally packed. Therefore, what is needed is a variable lengthballoon having a balloon recapture element to facilitate incrementaladjustment and/or protected and efficient repacking of the balloon.

The present invention comprises a variable length balloon with a balloonrecapture element that facilitates incremental adjustment to the lengthof exposed balloon as well as protected and efficient repacking of theballoon. The recapture elements may include rifling along the innersurface of the sheath, a smoothed edge at the distal end of the sheath,a tapered edge at the distal end of the sheath, a funnel-shaped tip atthe distal end of the sheath, or some combination thereof. Theserecapture elements may prevent wear to the balloon during re-sheathing.These recapture elements may also facilitate neat and tidy refolding andrepackaging of the balloon in the sheath. Coupled with the variablelength nature of the balloon, the recapture elements may facilitatemultiple deployments of the balloon at the same or different treatmentsites.

Alternatively, or in addition, it may be advantageous to use variousballoon sizes and configurations to prevent portions of the balloon fromescaping the sheath. For example, without limitation, a proximal portionof the balloon may be more compliant than a distal portion of theballoon. This may permit the proximal portion to inflate against aninner surface of the sheath and secure the relative position of theballoon.

When utilizing such catheter devices, it is sometimes desirable toinitially flush the catheter with saline or another liquid to ensurethat there is no air present in the catheter device. This is sometimesreferred to as “de-airing” the device. Air otherwise in the catheterdevice could inadvertently be introduced into the patient's vascularsystem and result in complications. In some cases, it would beadvantageous to instead use another biocompatible fluid for flushing thecatheter device such as, without limitation, carbon dioxide. Carbondioxide may be more readily available and cheaper as compared to salinein some situations.

Additionally, sometimes it would be advantageous to use alternativepositioning and exchanging systems with the catheter device. Forexample, a monorail type system might sometimes permit positioning ofthe catheter device or exchange the current catheter device with anotherdevice. Such a system may require a smaller length guidewire as comparedto a traditional system.

The present invention may further comprise a balloon having a proximalportion which is relatively compliant as compared to a distal portion.The increased compliance of the proximal portion may permit the proximalportion to expand against the inner wall of the sheath, therebypreventing a portion of the balloon from escaping the sheath.Alternatively, or in addition, the proximal portion may be larger orsmaller than the distal portion.

Various aspects of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In addition to the features mentioned above, other aspects of thepresent invention will be readily apparent from the followingdescriptions of the drawings and exemplary embodiments, wherein likereference numerals across the several views refer to identical orequivalent features, and wherein:

FIG. 1 is a side elevation view of a first end of a balloon catheterassembly;

FIG. 2 is an enlarged sectional elevation view of a second end of theballoon catheter assembly illustrated in FIG. 1;

FIG. 3 is a perspective view of a clamp of the balloon catheter assemblyillustrated in FIG. 1;

FIG. 4 is an enlarged sectional elevation view showing the clamp of theballoon catheter assembly illustrated in FIG. 1 in a locked condition;

FIG. 5 is an enlarged sectional elevation view similar to FIG. 4 showingthe clamp of the balloon catheter assembly in an unlocked condition;

FIG. 6 is a further enlarged sectional elevation view of a second end ofa balloon catheter assembly;

FIG. 7 is an enlarged sectional elevation view similar to FIG. 4,wherein a series of spaced indentations/protrusions are provided on oneside of the movable sheath;

FIG. 8 is an enlarged sectional elevation view similar to FIG. 7,wherein a series of annular spaced indentations/protrusions are providedabout the circumference of the movable sheath;

FIG. 9 is a sectional elevation view similar to FIG. 2 showing the endof the sheath in sealing engagement with a tapered insertion tip andindicating Detail A;

FIG. 10 is an enlarged view of the tapered insertion tip illustrated inDetail A of FIG. 9;

FIG. 11 is an enlarged view similar to FIG. 10 showing the sheathpartially retracted to expose the balloon;

FIG. 12 is a sectional elevation view similar to FIG. 9 showing anexemplary embodiment of a mechanical stop;

FIG. 13 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the mechanical stop;

FIG. 14 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the mechanical stop;

FIG. 15 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the mechanical stop;

FIG. 16 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the mechanical stop;

FIG. 17 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the mechanical stop;

FIG. 18 is an enlarged, side, sectional view of the sheath with theballoon removed to illustrate an exemplary embodiment of a balloonrecapture element;

FIG. 19 is an enlarged, side, sectional view similar to FIG. 18illustrating another exemplary embodiment of the balloon recaptureelement;

FIG. 19B is a side view of an exemplary pleated balloon for use with thedevice of FIG. 19, also illustrating section line 1-1;

FIG. 19C is a front, sectional view of the exemplary pleated balloontaken along section line 1-1 of FIG. 19B;

FIG. 20 is an enlarged, side, sectional view similar to FIG. 18illustrating another exemplary embodiment of the balloon recaptureelement; and

FIG. 20B is an enlarged, side, sectional view similar to FIG. 18illustrating another exemplary embodiment of the balloon recaptureelement;

FIG. 21 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon;

FIG. 22 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon;

FIG. 23 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon;

FIG. 24 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon; and

FIG. 25 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

Various embodiments of the present invention will now be described indetail with reference to the accompanying drawings. In the followingdescription, specific details such as detailed configuration andcomponents are merely provided to assist the overall understanding ofthese embodiments of the present invention. Therefore, it should beapparent to those skilled in the art that various changes andmodifications of the embodiments described herein can be made withoutdeparting from the scope and spirit of the present invention. Inaddition, descriptions of well-known functions and constructions areomitted for clarity and conciseness.

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which exemplary embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the size and relative sizes of layers and regions may beexaggerated for clarity.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof.

Embodiments of the invention are described herein with reference toillustrations that are schematic illustrations of idealized embodiments(and intermediate structures) of the invention. As such, variations fromthe shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,embodiments of the invention should not be construed as limited to theparticular shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 and FIG. 2 illustrate a balloon catheter assembly, indicatedgenerally at 10. The balloon catheter assembly is comprised of a firstend, illustrated in FIG. 1, and a second end, illustrated in FIG. 2. Theballoon catheter assembly 10 has an elongated shaft portion thatincludes an outer member 11 and an inner member 12. The outer member 11and the inner member 12 may both be tubular in shape, although such isnot required. The inner member 12 is disposed within the outer member11. Thus, an annular outer lumen is defined between the inner surface ofthe outer tubular member 11 and the outer surface of the inner tubularmember 12. Similarly, a cylindrical inner lumen is defined within theinner tubular member 12. The purpose for the outer and inner lumens willbe explained below.

In exemplary embodiments of the present invention, one or moreradiopaque markers 12 a may be provided on the inner tubular member 12.The radiopaque markers 12 a are conventional in the art and are providedto facilitate the determination of the location of the inner tubularmember 12 during a procedure using conventional fluoroscopy techniques.The radiopaque markers 12 a may be spaced in regular intervals. Further,one or more radiopaque markers 22 b may be provided on the expandedportion 22 a of the sheath 22 to facilitate the determination of thelocation of the sheath 22 using conventional fluoroscopy techniquesduring use. The radiopaque markers 12 a and 22 b may be monitored by theuser to determine how far the inner member 12 a, and thus the balloon15, is extended from the sheath 22 thereby permitting the user tomonitor how much of the balloon 15 is exposed for treatment of theaffected area.

An adapter 13 may be connected to a first end of the elongated shaftportion of the balloon catheter assembly 10. The adapter 13 isconventional in the art and is provided to facilitate access to both theouter and inner lumens during use of the balloon catheter assembly 10.For example, a guide wire 14 can be inserted into the inner lumen viathe adapter 13 and through a second end of the elongated shaft portionof the balloon catheter assembly 10, as shown in FIG. 2. The guide wire14 is conventional in the art and is provided to facilitate thepositioning of the balloon catheter assembly 10 at a desired locationfor use, such as within a blood vessel as described above.

The adapter 13 may comprise a luer lock or similar device configured tofacilitate the introduction of a fluid into the balloon catheterassembly 10. The fluid may be used to flush the balloon catheterassembly 10 prior to use. For example, without limitation, the fluid maybe used to remove any air from the balloon catheter assembly 10 prior toinserting any portion of the balloon catheter assembly 10 into thepatient's vascular system. The fluid may be any kind of biocompatiblefluid including, but not limited to, saline, carbon dioxide, and thelike. In exemplary embodiments, the luer lock and/or the adapter 13 maybe configured to accept a carbon dioxide cartridge for flushing theballoon catheter assembly 10.

The outer tubular member 11 includes an inflatable balloon 15. Theballoon 15 is conventional in the art and may be connected to the outertubular member 11 such that at least a portion of the inflatable balloon15 extends about an end portion of the inner tubular member 12. Theinterior of the balloon 15 communicates with the outer lumen of theballoon catheter assembly 10. As a result, an inflation fluid can beselectively introduced into the adapter 13 and through the outer lumento the interior of the balloon 15, causing it to inflate in a knownmanner. Additionally, the interior of the balloon 15 can be ventedthrough the outer lumen and the adapter 13 to the atmosphere, allowingit to deflate after use.

The balloon catheter assembly 10 includes an adjustable sheath assembly,indicated generally at 20. As be explained in detail below, theadjustable sheath assembly 20 is provided to selectively define aportion of the balloon 15 that is desired to be inflated during use. Toaccomplish this, the balloon catheter assembly 10 includes a clamp,indicated generally at 21, and a sheath 22. The clamp 21 is disposedabout the outer member 11 adjacent to the adapter 13 and the first endof the elongated shaft portion of the balloon catheter assembly 10. Thestructure and operation of the clamp 21 will be explained in detailbelow.

The sheath 22 may extend from the clamp 21 about the outer member 11toward the second end of the elongated shaft portion of the ballooncatheter assembly 10. In the illustrated embodiment, the sheath 22includes an expanded portion 22 a that is located adjacent to the secondend of the elongated shaft portion of the balloon catheter assembly 10.One or more optional radiopaque markers 22 b may be provided on theexpanded portion 22 a of the sheath 22 to facilitate the determinationof the location of the sheath 22 using conventional fluoroscopytechniques during use. Also, the expanded portion 22 a of the sheath 22may have an elastically expandable distal tip provided thereon that isexpanded in a conventional manner when the balloon 15 is inflated. Thestructure and operation of the optional elastically expandable distaltip will be explained in detail below.

Treatments to various size vascular zones of attention may be providedutilizing the present invention. To perform such treatments, a user mayfirst provide an intravascular catheter device consistent with thepresent invention. Next, the user may direct the catheter to apre-determined zone of attention within a person's vascular system. Thenthe user may move the sheath relative to the balloon so to selectivelyexpose a portion of the balloon for inflation. The user may nexttemporarily secure the sheath relative to the balloon. The user may theninflate the balloon. In exemplary embodiments of the present invention,these steps may include providing a medical treatment device, such asbut not limited to a stent, in conjunction with the present invention.The medical treatment device may be deployed when the balloon isinflated, or it may be deployed as another step. In either case, theballoon may then be deflated and removed.

The present invention may also provide a method for minimizing or alltogether eliminating premature activation, elution, dilution, or removalof a drug coating on the balloon and the medical treatment device. To doso, first the user may provide an intravascular catheter deviceconsistent with the present invention. Next, the user may direct thecatheter to the pre-determined zone of attention within the person'svascular system. Then the user may move the sheath relative to theballoon so to selectively expose a portion of the drug coated balloon orthe medical treatment device for activation. The balloon may be inflatedto place the outer surface of the balloon and the medical treatmentdevice in contact with the surrounding blood vessel wall. The balloonmay be deflated and removed. It is notable that while the aforementionedmethod is described with the medical treatment device, such is notrequired.

FIG. 3 illustrates the external structure of an exemplary embodiment ofthe clamp 21. As further illustrated in FIG. 4 and FIG. 5, the clamp 21includes a housing 30 through which the outer member 11 of the elongatedshaft portion of the balloon catheter assembly 10 extends. The housing30 includes a push button 31 and a tip 30 a. The tip 30 a may include aprotective member 25 that permits the passage of the sheath 22. Inexemplary embodiments of the present invention, the sheath 22 isconnected directly to the tip 30 a. Thus, the housing 30 of the damp 21is connected to the sheath 22 for movement therewith, as will beexplained in detail below.

FIG. 4 and FIG. 5 illustrate the internal structure of an embodiment ofthe clamp 21. The housing 30 of the damp 21 also includes a pair ofbutton supports 30 b, within which respective manually operable pushbuttons 31 are supported for inward and outward movement relative to thehousing 30. In the illustrated embodiment, each of the button supports30 b is generally hollow and cylindrical in shape, and each of the pushbuttons 31 is generally cylindrical in shape. However, the buttonsupports 30 b and the push buttons 31 may have any desired shape orcombination of shapes. The purpose for the push buttons 31 will beexplained below.

The housing 30 of the clamp 21 further includes a pair of actuator armsupports 30 c, upon which respective actuator arms 32 are supported forpivoting movement relative to the housing 30. In the illustratedembodiment, each of the actuator arm supports 30 c is a generallycylindrical protrusion that extends inwardly within the housing 30.However, the actuator arm supports 30 c may have any desired shape orcombination of shapes. Each of the illustrated actuator arms 32 isprovided with a pair of legs 32 a that define a pocket. The actuator armsupports 30 c of the actuator arms 32 are respectively received withinthe pockets defined by the pairs of legs 32 a of the actuator arms 32.Thus, as will be explained in detail below, the actuator arms 32 arerespectively supported on the actuator arm supports 30 c of the housing30 for independent pivoting movement relative thereto.

The first ends of the actuator arms 32 are respectively disposedadjacent to the inner ends of the push buttons 31. The actuator arms 32also include respective second ends that are disposed remotely from thefirst ends. In the illustrated embodiment, respective engagement pads 33are secured to the inner surfaces of the second ends of the actuatorarms 32. The engagement pads 33 may be formed from any desired materialor combination of materials and may, if desired, be omitted entirely.However, it is preferred that the engagements pads 33 be formed from amaterial having a relatively high coefficient of friction, such asrubber. The purpose for the engagement pads 33 will be explained below.

Lastly, the housing 30 of the clamp 21 may include a pair of springs 34that independently bias the two actuator arms 32 toward each other. Inthe illustrated embodiment, each of the springs 34 is formed from a flatpiece of resilient material, such as a metallic material, that has beendeformed to achieve a desired shape and bias. However, the springs 34may be formed from any desired material or combination of materials andtake any shape. The springs 34 may have first ends that are receivedwithin respective spring supports 30 d provided on the inner surface ofthe housing 30. The springs 34 also may have second ends that bearinwardly upon respective outer surfaces of the second ends of theactuator arms 32. The purpose for the springs 34 will be explainedbelow.

FIG. 4 illustrates the clamp 21 of the balloon catheter assembly 10 in alocked condition. In this locked condition, the second ends of thesprings 34 bear inwardly upon respective outer surfaces of the secondends of the actuator arms 32. As a result, the engagements pads 33 areurged inwardly toward one another, as shown at 35, so as to engage andmay exert a force on opposed portions of the outer surface of the outermember 11 of the balloon catheter assembly 10, which extends through theinterior of the housing 30 of the clamp 21. As mentioned above, theengagements pads 33 are preferably formed from a material having arelatively high coefficient of friction. Thus, when the clamp 21 of theballoon catheter assembly 10 is in the locked condition, the outermember 11 of the balloon catheter assembly 10 is hindered or whollyprevented from moving axially relative to the housing 30 of the clamp21. As mentioned above, the housing 30 of the clamp 21 is connected atthe tip 30 a to the sheath 22 for movement therewith. Accordingly, whenthe clamp 21 of the balloon catheter assembly 10 is in the lockedcondition, the outer member 11 of the balloon catheter assembly 10 isalso prevented from moving axially relative to the sheath 22.

FIG. 5 illustrates the clamp 21 of the balloon catheter assembly 10 inan unlocked condition. To achieve this unlocked condition, a user of theballoon catheter assembly 10 may apply inwardly directed forces, asshown at 36, against the manually operable push buttons 31. These forcesovercome the forces exerted by the springs 34 and cause the actuatorarms 32 to pivot such that the engagements pads 33 are moved out ofengagement, as shown at 37, with the opposed portions of the outersurface of the outer member 11 of the balloon catheter assembly 10.Thus, when the damp 21 of the balloon catheter assembly 10 is in theunlocked condition, the outer member 11 of the balloon catheter assembly10 is permitted to move axially relative to the housing 30 of the damp21. As mentioned above, as the housing 30 of the clamp 21 may beconnected at the tip 30 a to the sheath 22 for movement therewith, whenthe clamp 21 of the balloon catheter assembly 10 is in the unlockedcondition, the outer member 11 of the balloon catheter assembly 10 isalso permitted to move axially relative to the sheath 22.

Although this invention has been described in the context of theillustrated clamp 21, it will be appreciated that this invention may bepracticed with any other desired structure for preventing the balloon 15from slipping in relation to the sheath 22. For example, a variety ofknown structures may be used for this purpose. Some of such knownstructures include a duckbill pinch, a spring-activated clamp, a screwmechanism onto catheter, a Tuohy-Borst type of valve, and the like.Furthermore, it is possible to practice this invention without any clamp21.

FIG. 6 illustrates a second end of the balloon catheter assembly,indicated generally at 10′, in accordance with this invention. Likereference numbers are used to indicate components that are the same asdescribed above. As shown therein, the second end of the modifiedballoon catheter assembly 10′ has a collar 40 provided thereon. Thepurpose of the collar 40 is to prevent the sheath 22 from splitting orotherwise being deformed or damaged as a result of the pressure forceexerted by the balloon 15 when it is inflated. The illustrated collar 40is tubular in shape and extends completely about the end of the sheath22 where the balloon 15 is located. However, it will be appreciated thatthe collar 40 may have any desired shape and may be located at anydesired position on the sheath 22 or cover any desired portion of thesheath 22. The collar 40 may be formed from any desired material, suchas a metallic material, a high strength aramid fiber material (such asis commercially available under the Kevlar® brand name), a highdurometer plastic material, or the like, If desired, the collar 40 maybe formed from a radiopaque material, allowing it to function as amarker for the distal tip of the sheath 22. If desired, the distal tipof the sheath 22 may be provided with a smooth edge (not shown) so asnot to present a sharp edge toward the balloon 15.

The tip of the balloon 15 may fit snugly into the end of the sheath 22so as to provide a watertight engagement therebetween. Such a watertightengagement would maintain the integrity of the interior compartment ofthe balloon catheter assembly 10 during its insertion within a bloodvessel or other portion of a body and during travel to the treatmentsite. This may be utilized to maintain a dry interior. Maintaining theinterior compartment of the balloon catheter assembly 10 dry facilitatesthe use of conventional drug-coated balloons, stents, and other devices.The coatings provided on such devices are, in some instances, activatedby contact with blood and water. In known catheter assemblies, asignificant amount of the drugs provided on the balloons, stents, andother devices can be eluted during the initial insertion of the catheterassembly through blood vessels having flowing blood. The watertightengagement of this invention allows for minimal elution of the drugsduring the initial insertion of the balloon catheter assembly 10 andmaximal delivery of the drugs to the desired site. As will be explainedin greater detail in subsequent figures, a sealed engagement mayalternatively be obtained by the use of a tapered insertion tip 60. Alubricious coating may be provided between the sheath 22 and the outersurface of the balloon 15, such that the lubricious coating may reduceor eliminate disturbance to the drug coating when the balloon 15 ismoved relative to the sheath 22.

The sheath 22 may protect the various components of the adjustablesheath assembly 20 when moving through the persons' vascular system. Thesheath 22 may also protect any drug coating provided on the outersurface of the balloon 15 from being prematurely scraped off, eluted, oractivated such as, without limitation, by contact with the persons'bodily fluids or vascular structures. Furthermore, the sheath 22 mayprotect the adjustable sheath assembly 20 and/or any drug coatingprovided on the balloon 15 from contact with the procedural sheath thatmay be used over the adjustable sheath assembly 20. The sheath 22 mayalso protect the adjustable sheath assembly 20 and/or any drug coatingprovided on the balloon 15 from contact with vascular walls of theperson, particularly when navigating sinuous or narrow passages. Thesheath 22 may also protect the adjustable sheath assembly 20 and/or anydrug coating provided on the balloon 15 from contact with other objectsin the persons' vascular system, such as but not limited to, blockages.While the sheath 22 is described as protecting the components of theadjustable sheath assembly 20, it should be appreciated that the sheath22 may similarly protect the persons' vascular system from the variouscomponents of the adjustable sheath assembly 20.

FIG. 7 illustrates one side of the outer member 11 provided with aplurality of spaced indentations or protrusions, indicated generally at50. The indentations or protrusions 50 may have any desired shape orsize (or combination of shapes and sizes) and may be provided at anydesired location(s) on the one side of the outer member 11. Any numberof indentations or protrusions 50 is contemplated. The indentations orprotrusions 50 are adapted to cooperate with one or more inwardlyextending portions 32 b provided on either or both of the actuator arms32. Thus, when the clamp 21 of the balloon catheter assembly 10 is inthe locked condition, the inwardly extending portions 32 b provided oneither or both of the actuator arms 32 engage one or more of theindentations or protrusions 50. As a result, the outer member 11 of theballoon catheter assembly 10 is prevented from moving axially relativeto the housing 30 of the clamp 21. Conversely, when the clamp 21 of theballoon catheter assembly 10 is in the unlocked condition, the inwardlyextending portions 32 b provided on either or both of the actuator arms32 do not engage one or more of the indentations or protrusions 50. As aresult, the outer member 11 of the balloon catheter assembly 10 ispermitted to move axially relative to the housing 30 of the clamp 21.

FIG. 8 illustrates a series of annular spaced indentations orprotrusions, indicated generally at 55. The indentations or protrusions55 may have any desired shape or size (or combination of shapes andsizes) and may be provided at any desired location(s) on the outermember 11. Any number of indentations or protrusions 55 is contemplated.The indentations or protrusions 55 are adapted to cooperate with one ormore of the inwardly extending portions 32 b provided on either or bothof the actuator arms 32. Thus, when the clamp 21 of the balloon catheterassembly 10 is in the locked condition, the inwardly extending portions32 b provided on either or both of the actuator arms 32 engage one ormore of the indentations or protrusions 55. As a result, the outermember 11 of the balloon catheter assembly 10 is prevented from movingaxially relative to the housing 30 of the clamp 21. Conversely, when theclamp 21 of the balloon catheter assembly 10 is in the unlockedcondition, the inwardly extending portions 32 b provided on either orboth of the actuator arms 32 do not engage one or more of theindentations or protrusions 55. As a result, the outer member 11 of theballoon catheter assembly 10 is permitted to move axially relative tothe housing 30 of the clamp 21.

The annular spaced indentations or protrusions 55 may be a series ofidentical annular spaced indentations or protrusions 55. Each section ofthe annular spaced indentations or protrusions 55 may be defined by atubular section with an outer diameter smaller than the outer diameterof the outer member 11, a conical section with an initial outer diameterequal to the smaller outer diameter of the previous section,transitioning to an outer diameter substantially equal to the outerdiameter of the outer member 11, and finally, a second tubular sectionwith an outer diameter substantially equal to the outer diameter of theouter member. This design allows for the inwardly extending portions 32b to ratchet as each section of the annular spaced indentation orprotrusion 55 passes the inwardly extending portions 32 b. This mayprovide the user with tactile and audible feedback as each sectionpasses through the inwardly extending portion 32 b. In the illustratedembodiment this would prevent the clamp 21 from moving distally relativeto the balloon catheter assembly 10. It is contemplated that the annularspaced indentations or protrusions 55 may be reversed such that theindentations or protrusions 55 prevent the clamp 21 from movingproximally relative to the balloon catheter assembly 10.

FIG. 9, FIG. 10, and FIG. 11 illustrate a modified end of the adjustablesheath assembly 20′ with the tapered insertion tip 60. In FIG. 9 andFIG. 10, the end of the adjustable sheath assembly 20′ is in sealingengagement with the tapered insertion tip 60. FIG. 11 is similar to FIG.10 but shows the end of the adjustable sheath assembly 20′ partiallyretracted to expose the balloon 15 in the manner described above. One ormore radiopaque markers (not shown) may be placed on the taperedinsertion tip 60 and monitored using conventional fluoroscopy techniquessuch that the user may determine the distance, shown in FIG. 11 as “D”,between the sheath 22 a and the tapered insertion tip 60. This alsopermits the user to determine the exposed length of the balloon 15.

The sheath 22 and tapered insertion tip 60 may protect the drug coatingor drug coated devices such that the drug coating is not activated,eluted, diluted, or removed when the balloon catheter assembly 10 isplaced into the blood vessel. In exemplary embodiments of the presentinvention, the balloon 15 alone may provide a sealing engagement withthe sheath 22. The balloon catheter assembly 10 may additionallycomprise a lubricious coating provided between the sheath 22 and theballoon 15 to facilitate the movement of the balloon 15 relative to thesheath 22 by reducing or eliminating disturbance to the drug coating. Inexemplary embodiments of the present invention, the lubricious coatingmay additionally or alternatively be combined with or placed over thetop of the medicated coating.

FIG. 12 illustrates the adjustable sheath assembly 20 of the ballooncatheter assembly 10, further comprising a mechanical stop. Themechanical stop may comprise an annulus 23 and a block 38. A sheathlumen may be defined as the opening between the outer surface of balloon15 and the expanded portion 22 a. In exemplary embodiments of thepresent invention, there may be no sheath lumen, as the sheath 22substantially fits the curvature of the balloon 15. The annulus 23 maybe located on the distal end of the expanded portion 22 a. The annulus23 may comprise an annual member located on the inner surface of theexpanded portion 22 a having a thickness such that it protrudesinwardly, thereby restricting the sheath lumen. The stop 38 may comprisea corresponding annual member 38 located on the outer diameter of theballoon 15, though any shape capable of frictionally engaging theannulus 23 is contemplated. The outer dimension of the stop 38 has anouter diameter larger that the lumen created by the annulus 23. In suchan embodiment, the outer diameter of the corresponding stop 38 isconfigured such that it frictionally engages annulus 23, therebypreventing the balloon 15 from extending beyond the annulus 23.

FIG. 13 illustrates another exemplary embodiment of the presentinvention in which the assembly 10 further comprises one or more ridges28 located on the outer surface of the balloon 15 that extend verticallytherefrom. The mechanical stop may comprise an annular shaped pointedmember 23 b that it protrudes inwardly from the inner surface of thedistal end of the expanded portion 22 a, thereby restricting the sheathlumen, and the ridges 28. Further, the pointed shape of the pointedmember 23 b may be complementary to the shape of each of the ridges 28.As the balloon 15 is advanced relative to the sheath 22, the pointedmember 23 b may selectively secure the balloon 15 by frictionallyengaging each of the ridges 28. In exemplary embodiments, the ridges 28are formed as part of the balloon 15. Alternatively, the ridges 28 maybe separately formed and attached to the outer diameter of balloon 15.Any number of ridges 28 is contemplated. Additionally, the ridges 28 maybe equally spaced apart along balloon 15, though any spacing iscontemplated. The series of ridges 28 may be comprised of a sufficientlyrigid material such that each ridge 28 may not pass through the lumencreated by the pointed member 23 b without the user exerting a force onthe assembly 10 such that the ridge 28 or the pointed member 23 b may besufficiently deformed to pass though the lumen created by pointed member23 b. This force may be exerted by the user directly on the outer member11. Alternatively, this force may be exerted by the user on the outermember by use of the clamp 21.

FIG. 14 illustrates another exemplary embodiment wherein the balloon 15comprises a series of valleys 28 b located on the outer diameter of theballoon 15. The valleys 28 b reduce the thickness of the balloon 15 suchthat outer diameter of the balloon 15 is reduced. Any number of valleys28 b is contemplated. Said valleys 28 b may be equally spaced apartalong the balloon 15, though any spacing is contemplated. A pointedmember 23 c may selectively secure movement of the balloon 15 relativeto the sheath 22 by frictionally engaging each of the valleys 28 b asthey move through the lumen created by the pointed member 23 c. Theshape of the pointed member 23 b may be formed complementary to the voidcreated by each of the valleys 28 b. The pointed member 23 c may becomprised of a sufficiently flexible material such that each of thevalleys 28 b may not pass through the lumen created by the pointedmember 23 c until the user exerts force on the assembly such that thepointed member 23 c or the balloon 15 is sufficiently deformed to permiteach of the series of valleys 28 b to pass through the lumen created bythe pointed member 23 c. This force may be exerted by the user directlyon the outer member 11. Alternatively, this force may be exerted by theuser on the outer member by use of the clamp 21.

FIG. 15 illustrates another exemplary embodiment of the presentinvention wherein the mechanical stop comprises a block 24, which may beattached to the balloon 15. The block 24 may be attached to the outerdiameter of the balloon 15. The block 24 may be in the shape of a “T”such that the vertical section of the “T” extends vertically from theouter surface of balloon 15 and the horizontal portion of the “T” iscurved and secured to the outer surface of the balloon 15, though anyshape is contemplated. As the balloon 15 is extended from the expandedportion 22 a, the block 24 frictionally engages the mechanical stop 23.In other exemplary embodiments of the present invention, the block ofany shape may be used in place of the block 24.

FIG. 16 illustrates another exemplary embodiment of the mechanical stopcomprising a circumferential slot 29 located on the inner surface of theexpanded portion 22 a. The slot 29 may be configured to accommodate andfrictionally engage a collapsible block 24 b such that as the balloon 15is extended from the expanded portion 22 a, the collapsible block 24 bexpands and enters the slot 29, thereby preventing the balloon 15 fromfurther extending relative to the expanded portion 22 a. In exemplaryembodiments of the present invention, a collapsible orthotope, column,“T”, or other shape collapsible device may be used. The collapsibleblock 24 b, or the portion of the collapsible block 24 b extending intothe slot 29, may be spring loaded or otherwise biased into an expandedposition.

FIG. 17 illustrates another exemplary embodiment in which the mechanicalstop comprises a first and second portion 26 and 23 d. The first andsecond portion 26 and 23 d may be located on the outer surface of theballoon 15 and the inner surface of the sheath 22, respectively, and maycomprise a surface or a coating with a relatively high coefficient offriction. The remainder of the balloon 15 and the sheath 22 may furthercomprise a surface or a coating with a relatively low coefficient offriction such as a polymer, silicone, any kind of lubricant, or thelike. The first and second portions 26 and 23 d may comprise a rubber,polymer, or the like. Further, the first and second portions 26 and 23 dmay be comprised of a surface, a coating, or a surface texture toincrease the coefficient of friction such as bumps or the like. Thefirst portion 26 may be located towards the proximal end of the balloon15 relative to the clamp 21, though any location is contemplated. Thesecond portion 23 d may be located towards the distal end of the sheath22 relative to the clamp 21, though any location is contemplated. Theballoon 15 may extend relative to the sheath 22 until the first portion26 encounters and frictionally engages the second portion 23 d, therebypreventing the balloon 15 from traveling beyond.

Those having skills in the art will realize that these embodiments aremerely exemplary and that any device may be utilized with the presentinvention to prevent a section of balloon 15 from extending from thesheath 22. As such, any shape or design of mechanical stop capable ofpreventing a portion of balloon 15 from escaping the sheath 22 iscontemplated. Further, those skilled in the art will recognize that acombination of the aforementioned embodiments may be utilized.

FIG. 18 is an enlarged, side, sectional view of the adjustable sheathassembly 20 with the balloon 15 removed to better illustrate anexemplary balloon recapture element. The balloon recapture element maybe a rounded or smoothed distal end 70 of the sheath 22. Additionally,or in the alternative, the balloon recapture element may be a tapered orangled distal end 70 of the sheath. The rounded, smoothed, tapered, orangled distal end 70 may provide less frictional resistance and reducethe potential for wear and/or tearing of the balloon 15 when the balloonis being placed back into the sheath 22 and/or the exposed length of theballoon 15 from the sheath 22 is being adjusted.

FIG. 19 illustrates another exemplary embodiment of the balloonrecapture element. The balloon recapture element may comprise rifling 74located on the inner surface of the sheath 22. In exemplary embodimentsof the present invention, the rifling 74 is spiral shaped and extendsalong at least a portion of the sheath 22. However, there may be anynumber of rifles 74, along any length of the sheath 22. Further, therifling 74 may be in any configuration, including but not limited to,any slope angled between 0 degrees and 90 degrees.

FIG. 19B and FIG. 19C illustrate an exemplary pleated balloon 15′ foruse with the rifling 74 of FIG. 19. In exemplary embodiments of thepresent invention, the rifling 74 may be configured to mate with anumber of pleats 72 located on the outer surface of the balloon 15′. Anysize, number, shape, or configuration of the pleats 72 is contemplated.The pleats 72 may be configured to fit into the rifling 74 such that thedistance the balloon 15′ protrudes from the sheath 22 may beincrementally and predictably increased or decreased by advancing orretracting the balloon 15′ along the rifling 74 relative to the sheath22. In other exemplary embodiments of the present invention, the rifling74 may mate and interact with the ridges 28, blocks 24, collapsibleblocks 24 b, valleys 28 b, stop 38, or other stop mechanism.Additionally, the rifling 74 may permit the balloon 15′ to be neatlyfolded and repackaged upon retraction into the sheath 22. For example,without limitation, the rifling 74 may be patterned such that theballoon 15′ is forced along a track that encourages or forces theballoon 15′ to be folded in a desired manner for efficient packing. Suchfolding and packing may be further facilitated by preexisting creases inthe balloon 15′. Regardless, the rifling 74 may reduce or prevent thepotential for wear, tearing, or premature failure of the balloon 15′,thus permitting the balloon 15′ to be successively redeployed at thesame or other treatment sites.

FIG. 20 and FIG. 20B illustrate another embodiment of the balloonrecapture element where the sheath 22 may be formed with a funnel-shapedtip. The funnel-shaped tip may take the form of an enlarged section 76whereby the diameter is increased over a length of the sheath 22 andthen the diameter is held constant over a second length of the sheath22. Alternatively, the funnel-shaped tip may take the form of adiametrically increasing length 78 of the sheath 22. In this way theballoon 15 may be gradually forced to reduce in size as it travels backinto the sheath 22, resulting in a more easily recaptured balloon 15.This may reduce or prevent the potential for wear, tearing, or prematurefailure of the balloon 15, thus permitting the balloon 15 to besuccessively redeployed at the same or other treatment sites.

FIG. 21 is a sectional elevation view similar to FIG. 12 showing anotherexemplary embodiment of the balloon 15. In particular, the balloon 15may comprise a proximal portion 15A and a distal portion 15B. While theproximal portion 15A is illustrated as having a larger outer diameter ascompared to the distal portion 15B, it is contemplated that the proximalportion 15A and the distal portion 15B may have the same size outerdiameter. It is further contemplated that the proximal portion 15A mayhave a smaller outer diameter as compared to the distal portion 15B.

The proximal portion 15A may be located proximal to the clamp 21relative to the distal portion 15B. In exemplary embodiments, theproximal portion 15A may be relatively compliant compared to the distalportion 15B. This may permit the proximal portion 15A to expand againstthe inner surface of the sheath 22, such as the expanded portion 22 a.This may prevent the proximal portion 15A of the balloon 15 fromescaping the sheath 22. In other exemplary embodiments, the distalportion 15B may be relatively compliant compared to the proximal portion15A. This may permit the distal portion 15B to expand to a larger sizebefore the proximal portion 15A contacts the inner surface of the sheath22.

The proximal portion 15A may comprise the first portion 26 or a similararea having a relatively high coefficient of friction. Likewise, theexpanded portion 22 a of the sheath 22 may comprise the second portion23 d or similar area having a relatively high coefficient of friction.For example, Without limitation, the first and second portions 26 and 23d may be comprised of a rubber, a material having a high degree oftexture, or the like. In this way, when the proximal portion 15A isexpanded, the first portion 26 is placed into contact with the secondportion 23 d. As the pressure of the balloon 15 increases, the normalforces between the first and second portions 26 and 23 d may increase,thereby increasing the associated frictional forces. Any number of firstand second portions 26 and 23 d may be located on the balloon 15 at anylocation. It is further contemplated that the entire proximal portion15A may be comprised of a material having a relatively high coefficientof friction.

Alternatively, or in addition, the proximal portion 15A and the distalportion 15B may have different size outer diameters. In one exemplaryembodiment, the proximal portion 15A may be larger than the distalportion 15B such that the proximal portion 15A first comes into contactwith the inner surface of the sheath 22. In another exemplaryembodiment, the distal portion 15B is larger than the proximal portion15A. In this way, the balloon 15 may be permitted to expand into alarger size before the proximal portion 15A contacts the inner surfaceof the sheath 22. These are merely examples and are not intended to belimiting. It is contemplated that the balloon 15 may be any size orshape and comprise any number of characteristic (compliance, strength,pressure rating, etc.) and may contain any number of portions havingdifferent sizes and shapes and comprise any number of characteristics.It is specifically contemplated that the proximal portion 15A and thedistal portion 15B may have the same size outer diameter.

FIG. 22 illustrates another exemplary embodiment of the sheath assembly20. The sheath assembly may comprise an attachment device 42. Theattachment device 42 may be located on the outer surface of the sheath22. In exemplary embodiments, the attachment device 42 may extend alongthe outer surface of the expanded portion 22 a. The attachment device 42may be configured to accommodate the guide wire 14. In particular, theattachment device 42 forms a tube, slit, or channel configured toaccommodate the guide wire 14. The tube, slit, or channel, for examplewithout limitation, may be tubular in shape, U-shaped, V-shaped, or thelike. The attachment device 42 may facilitate the use of a guide wire 14to position the balloon catheter assembly 10. The attachment device 42may further facilitate the exchange of the balloon catheter assembly 10with other medical devices.

FIG. 23 illustrates another exemplary embodiment of an attachment device42 b. In exemplary embodiments, the attachment device 42 b may be apass-through device. The attachment device 42 b may be a tube, slit, orchannel that permits the guide wire 14 to exit through the sheath 22,the balloon 15, and into the inner member 12 closer to the distal end ofthe adjustable sheath assembly 20. Advantageously, this approachrequires a shorter guide wire 14. This stands in contrast to theover-the-wire approach (also contemplated), where the guide wire 14exits near the clamp 21. It is contemplated that the attachment device42 b may be located anywhere along the catheter assembly 10. Forexample, without limitation, the attachment device 42 b may be locatedproximal to the balloon 15 such that the attachment device 42 b permitsthe guide wire 14 to pass through the sheath 22 and into the innermember 12. In exemplary embodiments, the guide wire 14 may enter throughthe attachment device 42 b, pass through the inner member 12, and exitthe distal end of the catheter assembly 10. In still other exemplaryembodiments, the attachment device 42 b may be configured to permit theguide wire 14 to extend through the sheath but not into the inner member12.

FIG. 24 and FIG. 25 illustrate other exemplary embodiments of anattachment device 42 c. In exemplary embodiments, the attachment device42 c may comprise a first slit 43 located along the sheath 22. The firstslit 43 may be located along the expanded portion 22 a, however anylocation is contemplated. In other exemplary embodiments, the first slit43 may be located along the portion of the sheath 22 between theexpanded portion 22 a and the clamp 21. Stated another way, the firstslit 43 may be located on the portion of the sheath 22 not housing theballoon 15.

The first slit 43 may be any size or shape. In exemplary embodiments,the first slit 43 is sized to substantially match the length of theballoon 15. In this way, the guide wire 14 will not get trapped orkinked when the balloon 15 is moved relative to the sheath 22. In otherexemplary embodiments, the first slit 43 is sized to accommodate theguide wire 14. In such embodiments, additional guide wire 14 may be fedinto or out of the attachment device 42 c to accommodate movement of theballoon 15 relative to the sheath 22. In such embodiments, the firstslit 43 may be shaped as a circle, though any shape is contemplated.

The first slit 43 may also extend into the balloon 15, however such isnot required. A second slit 45 may be located in the inner member 12,though such is not required. The second slit 45 may also be sized tosubstantially match the length of the balloon 15. In exemplaryembodiments, the first slit 43 is sized to substantially match thelength of the balloon 15. In this way, the guide wire 14 will not gettrapped or kinked when the balloon 15 is moved relative to the sheath22. In other exemplary embodiments, the second slit 45 may be sized toaccommodate the guide wire 14. In such embodiments, additional guidewire 14 may be fed into or out of the attachment device 42 c toaccommodate movement of the balloon 15 relative to the sheath 22. Insuch embodiments, the first slit 43 may be shaped as a circle, thoughany shape is contemplated. The second slit 45 may be the same or adifferent size and shape than the first slit 43.

A channel 44 may extend between the first slit 43 and the second slit45, however such is not required. The channel 44 may be configured toaccommodate the guide wire 14. The channel 44 may also be sized tosubstantially match the length of the balloon 15. In other exemplaryembodiments, the channel 44 may be sized to accommodate the guide wire14. The channel 44 may be the same or a different size than the firstslit 43 and/or the second slit 45. The channel 44 may be formed by sidewalls extending between the first slit 45 and the second slit 45.However, in other exemplary embodiments, the channel 44 is defined bythe space between the first slit 45 and the second slit 45.

The guide wire 14 may enter the adjustable sheath assembly 20 throughthe distal end thereof and may exit the adjustable sheath assembly 20through one or more of the: first slit 43, the channel 44, and thesecond slit 45.

The attachment device 42, 42 b, or 42 c may permit a shorter guide wire14 to be used. Normally, the guide wire 14 must extend from thetreatment site all the way back to the clamp 21 or the entrance/exitpoint into the persons' vascular system. Particularly in below the kneeapplications, which are contemplated, this may require a long guide wire14. Such guide wires 14 may not be commercially available or may beexpensive. Additionally, such guide wires may be cumbersome to use anddifficult to control. The use of the attachment device 42, 42 b, or 42 cmay provide an exit point for the guide wire 14 closer to the distal endof the adjustable sheath assembly 20 such that a shorter guide wire 14may be used. This may permit use with shorter guide wires 14 which maybe cheaper, more readily available, and easier to control.

It is notable that any of the aforementioned balloon recapture elementsillustrated and described with respect to FIGS. 18-23 may be used incombination with one another and in combination with any or all of theembodiments described herein.

Any embodiment of the present invention may include any of the optionalor preferred features of the other embodiments of the present invention.The exemplary embodiments herein disclosed are not intended to beexhaustive or to unnecessarily limit the scope of the invention. Theexemplary embodiments were chosen and described in order to explain theprinciples of the present invention so that others skilled in the artmay practice the invention. Having shown and described exemplaryembodiments of the present invention, those skilled in the art willrealize that many variations and modifications may be made to thedescribed invention. Many of those variations and modifications willprovide the same result and fall within the spirit of the claimedinvention. It is the intention, therefore, to limit the invention onlyas indicated by the scope of the claims.

What is claimed is:
 1. An intravascular balloon catheter devicecomprising: an inner member; an outer member disposed about the innermember and comprising a balloon, said balloon having a proximal portionand a distal portion, wherein the proximal portion of the balloon isconnected to the outer member and the distal end of the balloon isconnected to the inner member; a sheath disposed about the outer memberand adapted for movement relative to the balloon so as to selectivelyexpose the distal portion of the balloon for inflation; and a coatingcomprising a therapeutic agent located on the outer surface of at leastthe distal portion of the balloon; wherein at least the distal portionof the balloon fits snugly into the sheath so as to provide asubstantially watertight engagement between at least the distal portionof the balloon and the sheath when the distal portion of the balloon islocated within the sheath; wherein the sheath is configured to preventthe proximal portion of the balloon from inflating to a diameter largerthan the sheath.
 2. The device of claim 1 further comprising: a clampconfigured to selectively secure the sheath at a desired positionrelative to the balloon such that the distal portion of the balloon isexposed for inflation and the proximal portion of the balloon remainslocated within the sheath.
 3. The device of claim 1 wherein: theproximal portion of the balloon is comprised of a more compliantmaterial than the distal portion of the balloon.
 4. The device of claim1 wherein: the proximal portion of the balloon is configured to contactan inner surface of the sheath upon inflation.
 5. The device of claim 4further comprising: a first area located on an inner surface of thesheath; and a second area located on the outer surface of the proximalportion; wherein the first and second areas are comprised of a materialhaving a relatively high coefficient of friction as compared to theremainder of the balloon and sheath.
 6. The device of claim 1 furthercomprising: an adapter located adjacent to the clamp and configured tofacilitate access to both the outer member and the inner member.
 7. Thedevice of claim 6 wherein: the adapter comprises a luer lock.
 8. Thedevice of claim 7 wherein: the luer lock is configured to receive acartridge comprising pressurized carbon dioxide.
 9. The device of claim7 wherein: the luer lock is configured to receive a syringe comprising abiocompatible fluid.
 10. The device of claim 1 wherein: the proximalportion of the balloon is configured to inflate to a first maximumdiameter; the distal portion of the balloon is configured to inflate toa second maximum diameter; and the first maximum diameter is smallerthan the second maximum diameter.
 11. The device of claim 1 wherein: theproximal portion of the balloon has a first outer diameter; the distalportion of the balloon has a second outer diameter; and the first outerdiameter is smaller than the second outer diameter.
 12. The device ofclaim 1 further comprising: an attachment device configured to permitthe guide wire to pass through the sheath and into the inner member. 13.The device of claim 1 further comprising: an attachment device locatedon the outer surface of the sheath and configured to receive a guidewire.
 14. The device of claim 13 wherein: the attachment devicecomprises a slit located along the sheath to provide an exit point forthe guide wire and sized to match the length of the balloon.
 15. Anintravascular balloon catheter device comprising: an outer member; aballoon affixed to a distal end of the outer member and configured to beselectively inflated to a first diameter and selectively deflated to asecond diameter, wherein the first diameter is larger than the seconddiameter; an inner member disposed within the outer member; a sheathdisposed about the outer member and configured for movement relative tothe balloon so as to selectively expose a distal portion of the balloonfor inflation while the proximal portion of the balloon remains in thesheath; wherein the proximal portion of the balloon is more compliantthan the distal portion of the balloon.
 16. The device of claim 15wherein: the proximal portion of the balloon is comprised of a materialhaving a relatively high coefficient of friction as compared to thedistal portion of the balloon.
 17. The device of claim 15 furthercomprising: a coating comprising a therapeutic agent located on theouter surface of at least the distal portion of the balloon; wherein atleast the distal portion of the balloon fits snugly into the sheath soas to provide a substantially watertight engagement between at least thedistal portion of the balloon and the sheath when the distal portion ofthe balloon is located within the sheath.
 18. The device of claim 15further comprising: a clamp comprising a first and second actuator armthat are supported within a housing, and a plurality of spacedindications located on the outer member, wherein the first and secondactuator arms are configured to selectively engage the plurality ofspaced indentations.
 19. A method for treating various size vascularzones of attention with a single device comprising the steps of:providing an intravascular catheter comprising an inner member, an outermember disposed about the inner member and having an expandable balloonlocated on a distal end thereof, a sheath disposed about said balloonand configured to selectively expose a distal portion of the balloon forinflation while a proximal portion of the balloon remains in the sheath,and a clamp for selectively securing the sheath at various positionsrelative to the balloon; directing the catheter to a pre-determined zoneof attention within a person's vascular system; securing the sheathrelative to the balloon so to expose the distal portion of the balloonfor inflation while keeping the proximal portion of the balloon covered;and inflating the balloon such that the distal portion of the ballooninflates to a maximum diameter while the proximal portion inflates andcontacts an inner surface of the sheath.
 20. The method of claim 19wherein: the proximal portion of the balloon is comprised of a morecompliant material compared to the distal portion of the balloon; and acoating comprising a therapeutic agent is provided on the outer surfaceof at least the distal portion of the balloon.